Method and apparatus for implementing an unregulated dormant mode with output reset in a power converter
Granted: February 26, 2013
Patent Number:
8385088
An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the…
Controller with punctuated switching control circuit
Granted: February 19, 2013
Patent Number:
8379420
An example controller for use in a power supply includes a zero crossing detection (ZCD) circuit and a punctuated switching control circuit. The ZCD circuit is coupled to generate a ZCD signal in response to a zero-crossing of an ac input voltage of the power supply. The punctuated switching control circuit is coupled to the ZCD circuit to generate a switching signal to control a switch to regulate an output of the power supply. The punctuated switching control circuit generates the…
Method and apparatus to regulate an output voltage of a power converter at light/no load conditions
Granted: February 12, 2013
Patent Number:
8374006
An example controller for a primary side control power converter includes a feedback circuit, a driver circuit, and an adjustable voltage reference circuit. The feedback circuit is coupled to compare a feedback signal representative of a bias winding voltage of the power converter with a voltage reference. The driver circuit is coupled to output a switching signal to control a switch of the power converter to regulate an output of the power converter in response the feedback circuit. The…
Enhancement-mode HFET circuit arrangement having high power and high threshold voltage
Granted: February 5, 2013
Patent Number:
8368121
A circuit includes input drain, source and gate nodes. The circuit also includes a group III nitride enhancement-mode HFET having a source, drain and gate and a voltage shifter having a first terminal connected to the gate of the enhancement mode HFET at a common junction. The circuit also includes a load resistive element connected to the common junction. The drain of the enhancement-mode HFET serves as the input drain node, the source of the enhancement-mode HFET serves as the input…
Controller compensation for frequency jitter
Granted: February 5, 2013
Patent Number:
8368370
An example controller for use in a power supply in accordance with the present teachings includes a drive signal generator, a jitter signal generator and a compensator signal generator. The drive signal generator is coupled to output a drive signal having a switching period and a duty ratio to control switching of a switch that is to be coupled to the controller. The jitter signal generator is coupled to provide a jitter signal, where the switching period of the drive signal varies in…
Ultra low standby consumption in a high power power converter
Granted: February 5, 2013
Patent Number:
8369111
A power converter with low power consumption during a standby operating condition. An example power controller includes a main converter coupled to a dc input of the power converter to control a transfer of energy from the dc input of the power converter to a main output of the power converter. A standby converter is also included and is coupled to the dc input of the power converter to control a transfer of energy from the dc input of the power converter to a standby output of the power…
Apparatus and method for sensing of isolated output
Granted: January 15, 2013
Patent Number:
8355266
A controller for use in a power converter includes a control circuit to be coupled to a current controller coupled to an energy transfer element. A first, second or third current is enabled in the current controller in response to the control circuit. The first current is substantially zero, the second current is greater than the third current, and the third current is greater than the first current. The third current only partially discharges a capacitance coupled to a terminal coupled…
Apparatus and method for detecting a change in output voltage of an isolated power converter
Granted: December 25, 2012
Patent Number:
8339811
An output voltage sensor for use in a power converter controller includes a first pulse sampler circuit coupled to receive a feedback signal representative of an output of a power converter. The first pulse sampler circuit is coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal. A second pulse sampler circuit is coupled to receive the feedback signal representative of the output of the…
Dimmer-disabled LED driver
Granted: December 18, 2012
Patent Number:
8334658
A controller for use in a light emitting diode (LED) driver is disclosed. An example controller includes an input circuit coupled to receive an ac input signal from an ac source. A dimmer disabler circuit is included and is coupled to be responsive to the input circuit to detect an absence of a portion of an ac half cycle the ac input signal for one or more consecutive ac half cycles from the ac input signal. A regulator circuit is included and is coupled to control a switching of a…
Forward converter transformer saturation prevention
Granted: December 11, 2012
Patent Number:
8331116
A power converter in one aspect limits the magnetic flux in a transformer. A control circuit included in the power converter includes a pulse width modulator, a logic circuit and a saturation prevention circuit. The saturation prevention circuit asserts a first signal when a first integral value of the input voltage reaches a first threshold value and asserts a second signal after a delay time that begins when a difference between the first integral value and a second integral value of a…
Method and apparatus for time-differential comparison of an analog signal
Granted: December 4, 2012
Patent Number:
8324941
A time-differential analog comparator is disclosed. An example apparatus according to aspects of the present invention includes a source of a variable frequency signal having a frequency responsive to an analog input. A counting circuit is coupled to count cycles of the variable frequency signal. The counting circuit is coupled to count in a first direction for a first time interval and is coupled to count in a second direction opposite to the first direction for a second time interval…
Method and apparatus for input charge control of a power supply
Granted: December 4, 2012
Patent Number:
8325505
An example power supply includes an energy transfer element, a switch and a controller. The controller includes a logic circuit and a constant current control circuit. The logic circuit generates a drive signal to control the switch in response to a control signal. The constant current control circuit generates the control signal in response to a received input current sense signal, input voltage sense signal, and output voltage sense signal. An integrator included in the constant…
Method and apparatus to limit maximum switch current in a switching power supply
Granted: December 4, 2012
Patent Number:
8325498
An integrated circuit for use in a power supply includes a drive signal generator, a short on time detector, and an oscillator. The drive signal generator generates a drive signal in response to a clock signal. The short on time detector provides an output indicating that consecutive on times of the drive signal are short on times. An on time of the drive signal is a short on time if a switch current of the switch exceeds a current limit after a leading edge blanking period and if the on…
Layout design for a high power, GaN-based FET
Granted: November 27, 2012
Patent Number:
8319256
A FET includes a substrate, a buffer layer disposed on the substrate, a channel layer disposed over the buffer layer and a barrier layer disposed over the channel layer. Source, gate and drain electrodes are located over the barrier layer and extend in a longitudinal direction thereon. A portion of the channel and barrier layers define a mesa extending in the longitudinal direction and the source and drain electrodes extend beyond an edge of the mesa. The gate electrodes extend along an…
Pulse width modulator with two-way integrator
Granted: November 13, 2012
Patent Number:
8310319
An example two-way integrator includes a first current source, a second current source, a first offset current source, a second offset current source, a capacitor, a switching reference and a comparator. The capacitor integrates a sum of a first input current and a first offset current by charging with both the first current source and the first offset current source. The capacitor subsequently integrates a sum of the second input current and the second offset current by discharging with…
Method and apparatus for adjusting displacement current in an energy transfer element
Granted: November 13, 2012
Patent Number:
8310326
Example methods include calculating a first number of turns of a shield winding included in an energy transfer element of a power supply. A first number of turns of the shield winding is calculated for the power supply to have a low noise current in an input conductor of the power supply. The method then includes increasing the first number of turns to a second number of turns. The power supply is then operated, which generates a first voltage waveform of a voltage between the input…
Power supply circuit with a control terminal for different functional modes of operation
Granted: November 13, 2012
Patent Number:
8310845
A method of operation for flyback power converter includes operating a controller of the flyback power converter in a regulation mode when a control signal is below a first threshold. The control signal is provided as an input to a terminal of the flyback power converter. When the control signal is below a second threshold and above the first threshold, the controller is operated in a limiting mode. The controller is operated in an external command mode when the control signal is below a…
Method and apparatus for varying current limit to limit an output power of a power supply
Granted: November 13, 2012
Patent Number:
8310850
A power supply controller is disclosed. An example power supply controller includes an input voltage sense input coupled to sense an input voltage sense signal representative of an input voltage of a power supply. An output voltage sense input is coupled to sense an output voltage sense signal representative of an output voltage of the power supply. A current limit circuit is coupled to generate a current limit signal. The current limit signal is varied relative to a first ratio…
Power supply controller with an input voltage compensation circuit
Granted: November 6, 2012
Patent Number:
8305063
An example controller for a power supply includes a drive signal generator and a compensation circuit. The drive signal generator is to be coupled to control switching of a switch included in the power supply to regulate an output voltage of the power supply in response to a sensed output voltage such that the output voltage of the power supply is greater than an input voltage of the power supply. The compensation circuit is coupled to the drive signal generator and is also coupled to…
Single-stage power supply with power factor correction and constant current output
Granted: November 6, 2012
Patent Number:
8305787
An example controller includes a delayed ramp generator, an integrator, an arithmetic operator, and a drive signal generator. The integrator integrates an input current sense signal representative of an input current of the power supply to generate an input charge signal. The input current has a pulsating waveform with a period that is a switching period of a switch of the power supply. The arithmetic operator circuit generates an input charge control signal responsive to the input…
